Rajidae

Rajidae is a family of cartilaginous fishes in the order Rajiformes, commonly known as skates. The group comprises numerous species across several genera, distributed in temperate and warm seas worldwide, including Raja, Leucoraja, and Dipturus. Taxonomic revisions based on molecular data continue to refine the composition of the family.

Rajids are elasmobranchs with dorso-ventrally flattened bodies and broad pectoral fins that are fused to the head, giving a winglike outline. The eyes and spiracles sit on the upper surface, while the mouth and gill slits are on the underside. The tail is typically short, with small dorsal fins, and most species lack a spine or sting.

Reproduction in Rajidae is predominantly oviparous. Females lay eggs in leathery capsules, often called mermaid’s purses, which anchor to substate or seafloor. Embryos develop inside the capsules, feeding on yolk, with clutch size and maturation time varying by species and environmental conditions.

Habitat and distribution cover continental shelves and upper slopes in oceans worldwide, from shallow coastal zones to considerable depths, with a preference for soft substrates such as sand or mud and sometimes kelp beds. Diet typically includes mollusks, crustaceans, polychaetes, and small fishes, reflecting their benthic foraging habits.

Conservation and fisheries: many skate species are affected by commercial fisheries, either targeted or as bycatch. Several Rajidae species are assessed by the IUCN with varying conservation statuses. Management measures in some regions include bycatch reduction devices, size limits, and habitat protections.